Why do airlines make passengers check their carry-on at the gate?

Airlines often require passengers to gate-check carry-ons mainly because of aircraft size and capacity limitations, which affect how many bags can fit in overhead bins. Travel expert Gunnar Olson, host of the Thrifty Traveler Podcast, said this is common on shorter flights using regional aircraft that cannot handle the volume of carry-on luggage onboard. The practice is also tied to rising checked-bag fees, pushing more travelers to bring full-size bags into the cabin. Delta says boarding delays are the key factor and calls gate-checking an “always a last resort,” using optimization tools to anticipate bin space. If a flight is expected to be full, Delta offers free lobby kiosk check-in. Southwest typically requests bags only from later boarding groups. Delta and Southwest raised checked-bag fees this spring to $45 for the first bag, up $10.